Re: Loop Audio on iPhone
Re: Loop Audio on iPhone
- Subject: Re: Loop Audio on iPhone
- From: William Stewart <email@hidden>
- Date: Mon, 23 Feb 2009 13:17:01 -0800
The difference in size is HUGE in an environment like the iPhone. In
my case, this is the comparison:
Original looping WAV: 2.4MB
looping IMA4-CAF: 658KB
looping MP3: 384KB
For the sake of clarity
These differences are expected and have nothing to do with the
particular file type that is used (CAF, WAV, MP3) but rather is all
about the data format:
Linear PCM (in the WAV file) is the uncompressed version
IMA4 (in the CAF file) is a compressor that provides a 4 to 1
compression ratio:
(so 658KB * 4 is about the size of the uncompressed audio as you
would expect)
The MP3 data is about 6.25 times smaller than the linear pcm
(uncompressed) - which implies a bit rate of around 192 kbps (or
bigger) I guess (if this were 44.1K, stereo 16bit to start with) - its
hard to tell exactly because you don't describe the characteristics of
the source file.
Bill
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